Combined vacuum relief-valve.



i -N."7|4,34 5. Pafentedmv, 25, |902. V E. B. wHELAN L w. J. swElGAnn.

COMBINED VACUUM RELIEF VALVE.

. (Application'lld Feb. 7. 1901.

` (No Model.) L' Sheets-Shadi l.

zgzefL/E we ,i f. l 76mm@ Patented Nov. 25,1902. E. B. wHELAN.& w. J. swElGAnn.

COMBINED VACUUM RELIEF VALVE.

(Application-filed Feb, 7. 1901.)`

2 Sheets-Shui I2.

` [un model.)

Witness@ N-.ITED STATES ATENT OFFICE.

EUGENE B. WI'IELAN, OF OMAHA, NEBRASKA, AND WILLIAM J. SWEIGARD, OF PHILADELPHIA, PENNSYLVANIA.

COMBINED VACUUM RELIEF-VALVE.

SPECIFICATION forming' part 0f Letters Patent No. 714,345, dated November 25,1902.

Application filed February 7, 1901. Serial No. 46,436. (No model.)

To a/ZZ whom t may concern,.-

Be it known that we, EUGENE B. WHELAN, residing at Omaha, in the county of Douglas and State of Nebraska, and WILLIAM J.

SWEIGARD, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain useful Improvements in a Combined Vacuum Relief- Valve; and We do' hereby declare that the fol- Io lowing is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had 4 to the accompanying drawings, which form a part of this specification.

This invention relates to a new and useful improvement in air relief-valves for compound steam-engines; and the object is to provide an improved construction of air rezo lief-valve for the cylinders and steam-chest held to its seat by high-pressure steam and adapted when said `pressure is removed to permit the entrance of air to said cylinders and steam-chest and the exit of the same therefrom for the purpose of preventing vacuum and compression.

In the accompanying drawings, Figure lis a central sectional view of a valve embodying our invention, a portion of the low-pressure cylinder being shown in section; Fig. 2, a top plan View of the lvalve-housing; Fig. 3, a sectional View on the line Y Y, Fig. l; and Fig. 4, an4 end elevation of the cylinders and saddle of a compound locomotive with our 3 5 improved air relief-valve attached.

As ordinarily constructed, the low-pressure cylinders of compound engines are provided with ordinary relief-valves, Which are usually gravity or spring actuated and are 4'o known as puppet-valves,`and the objection to the use of these valves in connection with compound locomotives is that they do l not properly seat themselves when a small amount of steam is used in the operation of the locomotive. Further, in4 the use of the ordinary valves two or more are needed to supply the necessary air to the high and low pressure cylinders and the steam-chest. ln this class of engines it is highly desirable 5b that there be no pulsation of the air reliefvalves used in connection especially With the low-pressure cylinders, as this pulsation not only causes an unnecessary wearing and breakage of the valves, but it adds a factor of hazard to railroading at all times,and more especially in cold weather,when starting the locomotive and operating under a low pressure of steam, because of the escape of steam which arising as a vapor at theforward end of the locomotive obstructs the view and makes it exceedingly difficult for the engineer to see the signals and switches.

Now the aim of our invention is more par-` ticularly to provide an improved construction whereby the objectionable features of b5 the ordinary construction of valves are overcome, and in accomplishing this we provide the low-pressure cylinders with air reliefvalves Which are in communication With a high-pressure steam-supply, insuring a per- 7o fect seating and contact irrespective of the pressure Within the low-pressure cylinders. Our valve is also constructed and arranged to admit air to all of the cylinders-that is, the loW and high pressure cylinders and the 7 5 steam-chest-dispensing with the use of a number of valves. V

In the accompanying drawings we have shown at B a broken portion of a locomotive cylinder-saddle containing the high-pressure steam-channel 26, which in locomotive construction communicates With the steam-chest or cylinder 28, thence passing to the highpressure cylinder 29, and iinally entering the low-pressure cylinder 30. At some point, so S5 as to enter this high-pressure steam-channel 26, we insert the threaded stem O, forming part of our air relief-valve. Secured to this stem and forming a part thereof is the valvehousing proper, comprising the top l, the 9o spaced valve-seats 32 and 33, disposed one about the other for the double-seating valves 2 and 3. These valves are reduced intermediately of their seats or channeled, as shown in Figs. l and 3, so that the seats x and y only operate to close the escape-Ways. In-

termediately this housing isprovided with a partition 4, separating the Valves 2 and 3 and preventing the passage of steam from one end to the other of the cylinder with which they are connected. This partition is provided With an opening e adapted to receive the IOO l stem of a valve 6, as shown.

vthe intermediate Wall 33 are the threaded branches 23 and 24, providing escape-ways, the first communicating with the valve 2 and the latter with the valve 3. By means of these threaded branches the housing is coupled by couplings 19 and 2 1 to suitable pipes 18 and 20, one of these pipes communicating with one end of the low-pressure cylinder and the other with the opposite end of said cylinder.

It is understood by those familiar with the art that 'compound engines when drifting, by virtue of the pumping movement of the pistons, create a vacuum within each of the cylinders and steam-chest, and this is especially true of the low-pressure cylinders. In order to break the vacuum within the low-pressure cylinders and the connected high-pressure cylinders and the steam-chest while the locomotive is drifting, we provide our steam-pressure-controlled air relief-valve, which as soon as the engine begins to drift, the steam-supply having been cut off by the throttle-valve from the channel 26, drop from their seats, permitting a free entrance of air through the air-inlet openings and pipes 18 and 2O to the low-pressure cylinder, relieving the same and preventing the formation of a vacuum therein at each of its ends and also relieving` compression. valves 2 and 3 and through the stem Cinto the channel 26, which had been filled with steam before the supply was cut oit and from said channel to the steam-chest and high-pressure cylinder. As soonas the throttle-valve is again opened the steam passes into said channel 26 and forces said valves to their seats, shutting off the air-supply to steamchest and high and low pressure cylinders. It will thus be seen that the action of the valves in seating and 'unseating is controlled by the main throttle-valve which operates the engine.

It is not necessary to have both of the val ves 2 and 3 incased in one housing, as shown, as in some types of compound locomotives it is preferable to use said valves separated, the use of the single or double housing depending upon the particular type of compound locomotive with which the valve is used.

The pipes 18 and 2O need not necessarily be of the length shown in Fig. 4, as properlycored channels could be provided in the cylinder-castings, which could be connected with the valve-casing by a short length of pipe, as shown in Fig. 1, the low-pressure cylinder in this instance being uppermost.

In order to increase the efficiency of our improved valve, We provide the auxiliary Air would also pass around the valve 6, which rests Within an insertible threaded member 9, threaded into the lower portion of the housing 8. This valve works upon a stem 5, reciprocating below through the member 9 and entering above in the opening e in the core 4t. Said valve is provided with a seat z, as shown in Fig. 3, and is provided with the air-inlet openings 17, so that air may readily enter the lower portion of the housing 8, escaping through the inner openings 16 when the valve is raised from its seat by suction. While this valve 6 is desirable, it is not essential and may be dispensed with.

It will be noted that the valves 2 and 3 are provided with downwardly-projecting bosses 11 and 12, and these contact with the member 9 when the valves are unseated, which member 9 acts as a stop for said valves, limiting their downward movement. It will also be noticed that by our construction as the valves are held to their seats by a steam-pressure equal to that in use as supplied by the main throttle to operate the engine they will be firmly seated, irrespective of the varying ot' the pressure within the cylinders. Were these valves operated directly by pressure within the cylinders with which they are connected upon a low pressure of steam in the low-pressure cylinders the valves would not have a firm seating, and so permit the escape of acertain amount of steam. In our invention, however, as stated, it is absolutely immaterial how little or how much pressure there may be in the low-pressure cylinders, as the valves are held firmly to their seats as long as the high-pressure steam is within the channel 26. From this it will be noted, first, that the valves 2 and 3 are always under initial live-steam pressure as long as steam is within the channel 26 and are thus firmly seated; second, the valves remain open during the full period that the cylinders are receiving and discharging air, and there is absolutely no pulsation of the valves.

We do not desire to limit ourselves to the exact construction and arrangement of parts, as various modifications may be made With- Yout departing from the spirit and scope of our invention.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a compound steam-engine, the combination with the low and high pressure cylinders, of a valve-casing having a communication with the atmosphere, passages communicating with said casing and low and high pressure cylinders, an air relief-valve in said casing adapted to close said atmospheric communication when seated, and adapted when unseated to establish communication between the atmosphere and high and low pressure cylinders through said passages, the communication between the low-pressure cylinder and atmosphere being uninterrupted While the valve is unseated, and a live-steam sup- IOO IIO

ply for holding said valve to its seat, substantially as described.

2. In acompound steam-engine, the combination with the steam-chest and the high and low pressure cylinders, of a valve-casing having a communication with the atmosphere, passages communicating with said casing and the steam-chest and high and low pressure cylinders, an air relief-valve in said casing adapted to close said atmospheric communication when seated, and adapted when unseated to establish communication between the atmosphere and the steam-chest andhigh and low pressure cylinders through said passages, the communication between the atmosphere and the low-pressure cylinder being uninterrupted while the valve is unseated, and a live-steam supplyfor holding said valve to its seat, substantially as described;

3. In a compound stea1nengin.e, the combi nation with the high and low pressure cylinders, of a valve-casing having a communication with the atmosphere and provided with two spacedvalveseats,a don ble-seating valve in said casing having seats at its respective ends and reduced or channeled intermediately of said seats, a communication between one of said cylinders and said casing at a point intermediately of the seats of the valve, a communication between the other cylinder and the casing at a point on the opposite side of the valve to the air-inlet oi' the casing, and a live-steam supply for holding said valve to itsseat, substantially as described.

4. In a steam-engine, the combination with the steamchest and cylinder, of a valve-cas- `ing having communication with the atmos- `the opposite side of the valve to the air-inlet of said casing, and a live-steam supply for holding said valve to its seats, substantially `as described.

5. In a steam-engine, the combination with the cylinder, of a valve-casing having a communication with the atmosphere and provided with two spaced valvefseats, a double-seating valve in said casing having seats atits re spective ends, a communication between said cylinder and the valve-casing at a point intermediately of the seats of the valve, and a communication between a `live-steam ,supply `its respective ends and reduced or channeled intermediately of said seats, a communication between the low-pressure cylinder and the casing at a point intermediately of the seats of the valve, a communication between the stea r11-supply passage to said steam-chest and the casing at a point on the opposite side of the valve to the air-inlet of the casing, said valve being normally held to its seats by the live-steam pressure from said steam-supply passage and when unseated adapted to establ lish communication between the low-pressure cylinder and the atmosphere through said l'irst-mentioned communication and. to establieb-communication between the atmosphere and the highpressure cylinder and steamchest through the steam-supply passage and theV communication of the casing'therewith, substantially as described.

7. In a compound steam-engine, the combination of the high and low pressure cylinders and main steam-supply channel, of a valvecasing having an airinlet, a communication between said valve-casing and the low-pressure cylinder, a valve in said casing controlling the air-inlet, and a communication between the casing at a point below the valve and the main steam supply channel, said valvewhen unseated adapted to admit air' through said first-mentioned communication to the low-pressure cylinder and through said last-mentioned communication to the highpressure cylinder, substantially as described.

EUGENE B. WHELAN. WILLIAM J. SWEIGARD.

In presence 0f- GEORGE W. Suns, ETHEL SMITH. 

